These studies are designed to achieve several objectives: first, to obtain metabolic, physiologic, and pharmacologic information which would aid in the preservation and transfusion of stored platelets; second, to study the relation of various biochemical and pharmalogical factors on the function of platelets as measured by the release reaction; third, to elucidate the mechanism of the release reaction; and fourth, to gain general information about the mechanism of membrane-mediated cellular reactions. BIBLIOGRAPHIC REFERENCES: Schmukler, M., Zieve, P.D., and Jewett, P.B.: Induction of the Platelet Release Reaction by Concanavalin A: Relation of Con A Binding to Release and Modification of Release by ATP, PGE, and Amantadine. Biochem. Pharm. 25: 1819-1824, 1976. Schiffer, C.A., Whitaker, C.L., Schmukler, M., Aisner, T., and Hilbert, S.L. The Effect of Dimethyl Sulfoxide on in vitro Platelet Function. Thrombosis and Haemostasis 36: 221-229, 1976.